#define _CRT_SECURE_NO_WARNINGS 1
#include"stack.h"
void StackInit(Stack* ps)
{
	assert(ps);
	ps->a = NULL;
	ps->top = ps->capacity = 0;
}

void StackPush(Stack* ps, STDateType x)
{
	assert(ps);

	if(ps->top == ps->capacity)
	{
		int newcapacity = ps->capacity == 0 ? 4 : ps->capacity*2;
		STDateType* temp = (STDateType*)realloc(ps->a, sizeof(STDateType)*newcapacity);
		if (temp == NULL)
		{
			perror("malloc fail.\n");
			exit(-1);
		}
		ps->capacity = newcapacity;
		ps->a = temp;
	}
	ps->a[ps->top] = x;
	ps->top++;
}

void StackPop(Stack* ps)
{
	assert(ps);
	assert(!StackEmpty(ps));
	ps->top--;
}

STDateType StackTop(Stack* ps)
{
	assert(ps);
	assert(!StackEmpty(ps));
	return ps->a[ps->top - 1];
}

int StackSize(Stack* ps)
{
	assert(ps);
	return ps->top;
}

bool StackEmpty(Stack* ps)
{
	assert(ps);
	return ps->top == 0;
}


void StackDestory(Stack* ps)
{
	assert(ps);
	free(ps->a);
	ps->a = NULL;
	ps->top = ps->capacity = 0;
}